System And Method For High Output Laser Trimming

ABSTRACT

A system  10  and method for laser cutting a plurality of parts, for example metal chassis components, using a plurality of laser cutting apparatuses is provided. The system  10  includes a plurality of the laser cutting apparatuses  14  disposed in a single enclosed cell  12  for simultaneously trimming multiple parts. The system  10  also includes at least one inner chamber  22  and at least one set of double doors  16, 18  for transferring the parts in and out of the enclosed cell  12  without any light escaping the cell  12 . The parts are conveyed through the first door  16  to the inner chamber  22  while the second door  18  is closed, and through the second door  18  to the enclosed cell  12  while the first door  16  is closed. The system  10  also includes robots  24  continuously preloading and unloading the parts to maximize the laser trimming time.

CROSS-REFERENCE TO PRIOR APPLICATIONS

This U.S. Continuation Patent Application claims the benefit of U.S.National Stage patent application Ser. No. 15/035,579, filed May 10,2016, which claims the benefit of PCT International Patent ApplicationSerial No. PCT/US2014/064765, filed Nov. 10, 2014 and entitled “Systemand Method for High Output Laser Trimming,” which claims the benefit ofU.S. Provisional Patent Application Ser. No. 61/902,861, filed Nov. 12,2013 and entitled “System and Method for High Output Laser Trimming,”the entire disclosures of the applications being considered part of thedisclosure of this application and hereby incorporated by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates generally to a system and method for high outputlaser cutting.

2. Related Art

A laser cutting apparatus, such as a robotic laser, is often used totrim or otherwise cut parts formed from sheet metal, such as tubes,B-pillars, and other chassis components for automotive vehicles. Therobotic laser can comprise any type of laser capable of cutting themetal material, for example a fiber laser, disc laser, orneodymium-doped yttrium aluminum garnet (Nd:Y₃Al₅O₁₂) laser. A computernumeric controlled (CNC) arm including a laser can alternatively be usedto trim the metal parts. Such cutting processes are conducted in anenclosed cell so that humans are not exposed to light from the laser,which could be harmful.

Laser cutting using the robot or CNC arm typically provides accurate andprecise results. However, the equipment and floor space needed toconduct the laser cutting process requires high capital costs. Inaddition, since the laser should not operate when any doors to theenclosed cell are open, process time is lost each time the metal part ismoved into or out of the cell.

SUMMARY OF THE INVENTION

The invention comprises a laser cutting system for cutting a pluralityof parts with reduced capital costs and reduced process time. The systemincludes a cell enclosed by a plurality of first walls, and at least onelaser cutting apparatus disposed in the enclosed cell. At least oneinner chamber with a pair of double doors is disposed along the enclosedcell. The inner chamber is enclosed by at least one of the first wallsand at least one second wall. The double doors include a first doordisposed along one of the first walls enclosing the inner chamber forallowing the parts to pass therethrough, and a second door disposedalong one of the second walls enclosing the inner chamber also forallowing the parts to pass therethrough. Only one of the doors is openat a time while the laser cutting apparatus cuts the parts.

Prior to cutting a first part, the first part passes through one of thedouble doors and enters the inner chamber while the second door isclosed. Next, the first part passes through the second door and entersthe enclosed cell while the first door is closed. Since only one door isopen at a time, light from the laser does not escape the enclosed cell.Thus, the laser cutting apparatus can continue cutting the first partwhile a second part enters or exits the cell to maximize the lasercutting time, also referred to as “laser on time.”

The invention also provides a method for laser cutting a plurality ofparts. The method includes laser cutting at least one first part in theenclosed cell, maintaining at least one second part in the enclosed celladjacent the at least one first part while laser cutting the at leastone first part, and laser cutting the least one second part in theenclosed cell. The method further includes transferring at least onethird part through the first door and into the inner chamber while lasercutting the at least one first part or the at least one second part andwhile the second door connecting the inner chamber to the enclosed cellis closed. The double door system prevents the laser light from escapingand potentially contacting a human located outside of the enclosed cell.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated,as the same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a plan view of a robotic laser cutting system according to oneexemplary embodiment;

FIG. 2 is a side view of an enclosed cell showing double doors accordingto the exemplary embodiment;

FIG. 3 is a front view of two sets of the double doors according to theexemplary embodiment;

FIG. 4 is a front cross-sectional view of the enclosed cell according toan exemplary embodiment;

FIG. 5 is a plan view of the robotic laser cutting system according to asecond exemplary embodiment;

FIG. 6 is a plan view of a robotic laser cutting system according to athird exemplary embodiment;

FIG. 7 is a flow chart of an exemplary laser cutting method; and

FIG. 8 is a flow chart of another exemplary laser cutting method.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

The invention provides a high output system 10 for laser cutting variousparts, such as tubes, B-pillars, and other chassis components forautomotive vehicles. FIG. 1 is a plan view of the system 10 according toone exemplary embodiment. The exemplary system 10 includes a singleenclosed cell 12 containing at least one laser cutting apparatus 14 forcutting the parts, and typically a plurality of the laser cuttingapparatuses 14 in the single enclosed cell 12. The laser cuttingapparatuses 14 typically include a robotic laser. However, the system 10could alternatively employ at least two computer numeric controlled(CNC) arms each including a laser, instead of or in addition to therobotic lasers. Also, although the exemplary laser cutting system 10 istypically used to trim parts formed of metal, such as steel or aluminum,the system 10 could also be used to cut parts formed of other materials.In one exemplary embodiment, the system 10 is used to laser cut partsformed by high pressure die casting (HPDC) of aluminum or an aluminumalloy. In another embodiment, the system 10 is used to laser cut partsformed by low pressure die casting (LPDC) of aluminum or an aluminumalloy. The laser cutting step typically includes laser trimming theparts, but could include other types of cutting.

The system 10 includes at least one set of double doors 16, 18 forallowing the parts to enter and exit the enclosed cell 12 withoutletting any laser light escape the enclosed cell 12. Thus, the lasercutting apparatuses 14 can continuously trim one or more parts whileother parts enter and exit the enclosed cell 12.

The exemplary system shown in FIG. 1 includes four laser cuttingapparatuses 14 trimming the parts, but the system 10 could alternativelyinclude any number of laser cutting apparatuses 14, depending on theoutput desired, size and number of parts to be trimmed, and theavailable resources. In this embodiment, the laser cutting apparatuses14 are robotic lasers, and two of the robotic lasers simultaneously trimone part while the other two robotic lasers simultaneously trim anotherpart. The system 10 is capable of cutting one to ten parts at a time,depending on the number of laser cutting apparatuses 14 and the size ofthe parts. Disposing a plurality of the laser cutting apparatuses 14 inthe single enclosed cell 12 and cutting each part with multiple lasercutting apparatuses simultaneous and/or simultaneously cutting multipleparts provides for a shorter cutting time per part and reduces therequired floor space, compared to systems with only one laser cuttingapparatus 14 per enclosed cell 12.

The robotic lasers or lasers attached to the CNC arms can comprise anytype of laser capable of cutting metal, for example a fiber laser, disclaser, or neodymium-doped yttrium aluminum garnet (Nd:Y₃Al₅O₁₂) laser.The laser cutting apparatuses 14 of the exemplary embodiment surround acutting station 20 and are preferably coupled to a frame (not shown) andmounted to the ceiling of the enclosed cell 12. Alternatively, the lasercutting apparatuses 14 could be disposed on the floor of the enclosedcell 12, as shown in FIG. 4. Each robotic laser of the exemplaryembodiment includes a laser cutting head 15, also shown in FIG. 4, forcutting the metal parts. The cell 12 containing the laser cuttingapparatuses 14 is enclosed by a plurality of walls 11, referred to asfirst walls, which prevent any laser light from escaping the enclosedcell 12. Due to the plurality of laser cutting apparatuses 14 in thesingle enclosed cell 12, the system 10 requires less floor space andprovides a shorter process time, compared to systems with only one lasercutting apparatuses per cell.

The system 10 also includes at least one inner chamber 22 and at leastone set of the double doors 16, 18 for allowing the parts to enter andexit the enclosed cell 12 without any laser light escaping the enclosedcell 12. In the exemplary embodiments, the system 10 includes one innerchamber 22 on each side of the laser cutting station 20, and thus oneset of double doors 16, 18 on each side of the cutting station 20. Eachset of double doors 16, 18 includes a first door 16 and a second door18. Each inner chamber 22 is located between one of the first doors 16and one of the second doors 18. The inner chamber 22 is also enclosed bywalls 23, referred to as second walls, to prevent any laser light thathappens to enter the inner chamber 22 from escaping. In the exemplaryembodiment of FIG. 1, the first doors 16 are disposed along the samefirst wall 11 of the enclosed cell 12, and the first doors 16 connectthe inner chambers 22 to a part loading area 32. The second doors 18 areeach disposed along a second wall 23 facing parallel to the first door16 and connect the inner chambers 22 to the enclosed cell 12. Duringoperation of the laser cutting system 10, a part is conveyed through thefirst door 16 while the second door 18 is closed. Next, the first door16 closes, and the part is conveyed through the second door 18 into theenclosed cell 12 while the first door 16 is closed.

FIG. 2 is a side view of the double doors 16, 18, the inner chamber 22,and the enclosed cell 12 of the system 10 according to one exemplaryembodiment, wherein the doors 16, 18 are sliding doors. The first door16 is disposed vertically relative to the ground and slides up and downallowing the parts to enter and exit the inner chamber 22. The seconddoor 18 is disposed at an angle relative to the ground and relative tothe first door 16. The second door 18 also slides up and down allowingthe parts to enter and exit the enclosed cell 12. Disposing the seconddoor 18 at an angle allows a robot 24 to conveniently lift the parts outof the inner chamber 22 and place the parts back in the inner chamber 22after they have been trimmed. The doors 16, 18 can be designed such thatthe opening is above the door 16, 18, as shown on the left side of FIG.3, or below the door, as shown on the right side of FIG. 3. In thesystem 10 of FIG. 1, the opening is preferably below the first door 16to allow the parts to slide under the first door 16, and the opening ispreferably above the second door 18 to allow the robot 24 to lift theparts above the second door 18, in and out of the inner chamber 22.

Although the exemplary system 10 of FIG. 1 is shown with two innerchambers 22 and thus two sets of double doors 16, 18, the system 10could alternatively include one or more sets of double doors 16, 18. Inaddition, the inner chambers 22 are typically located inside of theenclosed cell 12, such that the first doors 16 are disposed along thefirst walls 11, and the second walls 23 enclosing the inner chambers 22and second walls 23 are located inside of the first walls 11. However,although not shown, the inner chambers 22 could be located outwardly ofthe enclosed cell 12, in which case, the second doors 18 and secondwalls 23 enclosing the inner chambers 22 are located outside of thefirst walls 11 and first doors 16.

Also in the exemplary embodiment of FIG. 1, a load slide 26 and loadingplatforms 28 are located adjacent to each set of double doors 16, 18.One loading platform 28 is disposed on each load slide 26. Anotherloading platform 28 can be disposed below the load slide 26 for storingparts to be loaded, as shown on the right side of FIG. 1. The parts areplaced on the loading platforms 28 and the load slides 26 convey theloading platforms 28 and parts through the double doors 16, 18. Eachload slide 26 moves through the associated first door 16, in and out ofthe inner chamber 22, while the associated second door 18 is closed.Alternatively, another means could be used to convey the parts into andout of the enclosed cell 12.

FIG. 1 also shows a human operator 30 loading and unloading the metalparts to and from the part loading platforms 28. The part loading area32 adjacent to each of the load slides 26, which is shown in FIG. 1 withhatched lines, is continuously scanned by a safety laser (not shown) toassure that no human or object is in the path of the load slide 26. Whenthe safety laser detects a human or object in the loading area 32, theload slide 26 is prohibited from moving. Once the operator 30 loads orunloads the metal parts from the part loading fixture 28, he or shesteps out of the loading area 32 and hits a palm button 33 allowing theload slide 26 to move again.

The exemplary system 10 of FIG. 1 also includes the robots 24 fortransferring the parts from the loading platforms 28 to the lasercutting station 20. In the embodiment of FIG. 1, the robots 24 arematerial handling robots (M-H robots), but the robots 24 could compriseanother device capable of automatically transferring the parts to andfrom the laser cutting station 20. In FIG. 1, one robot 24 is locatedbetween a first one of the inner chambers 22 and the laser cuttingstation 20, and another robot 24 is located between a second one of theinner chambers 22 and the laser cutting station 20 such that parts canbe conveyed to and from both inner chambers 22 simultaneously. However,the system 10 could be designed without the robots 24. For example, theload slide 26 or a conveyor could convey the parts directly from theinner chamber 22 to the laser cutting station 20.

The system 10 of FIG. 1 includes cutting platforms 34, 36 disposed on aconveyor 38 (shown in FIG. 4) which extends from the robots 24 to thelaser cutting station 20 for transferring the parts to and from thelaser cutting station 20. The cutting platforms 34, 36 and conveyor 38are designed such that a first cutting platform 34 is disposed at thelaser cutting station 20 below the laser cutting apparatus 14 while asecond cutting platform 36 is disposed to the left of the laser cuttingstation 20. Each platform 34, 36 includes a part setting fixture 40 formaintaining the parts precisely in a predetermined position for lasercutting. Each part setting fixture 40 typically includes a plurality oflocating pins and clamps for holding the parts in the predeterminedposition. The design of the part setting fixture 40 varies depending onthe type of part to be trimmed or otherwise cut. However, the partsetting fixture 40 preferably includes no clamps in the cutting path,such that the laser cutting apparatuses 14 can continuously trim orotherwise cut the parts without stopping. During operation, the robots24 transfer the parts from the inner chambers 22 to the cuttingplatforms 34, 36 and vice versa, and the cutting platforms 34, 36 slidealong the conveyor 38 to and from the laser cutting station 20.

FIG. 1 shows a first pair of parts 1 disposed on the first cuttingplatform 34 at the cutting station 20 beneath the laser cuttingapparatuses 14, and a second pair of parts 2 preloaded on the secondcutting platform 36 to the left of the cutting station 20. The lasercutting apparatuses 14 trim the first pair of parts 1 while the secondpair 2 of parts waits to the left of the cutting station 20. Once thefirst pair of parts 1 is trimmed, both cutting platforms 34, 36immediately slide to the right such that the second cutting platform 36and the second pair of parts 2 are disposed at the cutting station 20.The second pair of parts 2 is then trimmed, and while the second pair ofparts 2 is being trimmed, the robot 24 on the right side of the cuttingstation 20 unloads the previously trimmed first pair of parts 1 from thefirst cutting platform 34 and places them in the inner chamber 22. Inthe meantime, an untrimmed third pair of parts 3 has already been placedon the load slide 26, and the third pair of parts 3 is waiting in theinner chamber 22. The robot 24 then lifts the untrimmed third pair ofparts 3 from the inner chamber 22 and preloads them on the first cuttingplatform 34. Once the second pair of parts 2 is trimmed, the cuttingplatforms 34, 36 slide to the left such that the first cutting platform34 and the untrimmed third pair of parts 3 are located at the cuttingstation 20 and the second cutting platform 36 and the trimmed secondpair of parts 2 are located to the left of the cutting station 20. Thethird pair of parts 3 is then trimmed.

Next, the previously trimmed second pair of parts 2 is unloaded by therobot 24 on the left side of the cutting station 20 while the third pairof parts 3 is trimmed. The preloading, cutting, and unloading steps arerepeated continuously to maximize the laser cutting time, referred to asthe “laser on time.” The only time the laser cutting apparatuses 14 areoff is when the cutting platforms 34, 36 are sliding the parts along theconveyor 38, which is a very short period of time because there isalways a preloaded pair of parts waiting adjacent the cutting station20. Otherwise, the laser cutting apparatuses 14 are constantly on andcutting the parts.

The system 10 of FIG. 1 also includes other components which assist orimprove the laser cutting process. For example, tool stands 42 arelocated inside the enclosed cell 12 so that the laser cuttingapparatuses 14 can automatically change tools, such as their respectiveend effectors, in order to trim various different parts. A ventilationsystem 44 is also located inside of the enclosed cell 12. In theembodiment of FIG. 1, the ventilation system 44 is a 360° dust removalsystem coupled to the frame connecting the laser cutting apparatuses 14to the ceiling of the enclosed cell 12. The 360° dust removal systemefficiently removes dust, smoke, light particles, and heavy particlesfrom the enclosed cell 12. The ventilation system 44 could alternativelybe an air duct disposed over the laser cutting station 20, as shown inFIG. 4. A scrap conveyor 46 also extends from the laser cutting station20 to a waste container 48 for removing scrap metal from the cell 12.The scrap conveyor 46 extends through the walls of the cell 12 to thewaste container 48 which is located outside of the enclosed cell 12.Also, in proximity to the enclosed cell 12, is a plurality of laserpower sources 50; densification packages 52 with air valves, watervalves, and filter dryers for supplying clean air and water; and achiller 54 for cooling water to keep the laser cutting apparatuses 14and specifically the laser cutting heads 15 of the robotic lasers atsuitable temperatures. In addition, racks 62 for holding the untrimmedand trimmed parts are located outside of the enclosed cell 12, adjacentto the loading areas 32.

A master control panel 58 is located outside of the enclosed cell 12 forcontrolling all of the components of the system 10, including the lasercutting apparatuses 14, robots 24, doors 16, 18, load slides 26,conveyors 38, 46, and safety systems. The components of the system 10can be controlled automatically or semi-automatically, depending on thedesired output and resources available. In one preferred embodiment, themaster control panel 58 controls and replaces the componentsautomatically or semi-automatically. A power distribution panel 60 isdisposed adjacent the master control panel 58. Control boxes 56 for thelaser cutting apparatuses 14 are typically located between the two loadslides 26 outside of the enclosed cell 12. The control boxes 56 areconnected to the master control panel 58 and are accessible to theoperators 30.

As stated above, the laser cutting system 10, including the double doors16, 18 and the plurality of laser cutting apparatuses 14, can bemodified in view of available resources and desired output. For example,the system 10 could include only one pair of double doors 16, 18 and oneinner chamber 22. In addition, a single load slide 26 or conveyor 38could convey the parts directly from the inner chamber 22 to the lasercutting station 20 without the robots 24.

FIG. 5 illustrates the laser cutting system 110 according to anotherexemplary embodiment, which is less automatic and requires more laborthan the laser cutting system 10 of FIG. 1. Like the system 10 of FIG.1, the system 110 of FIG. 5 includes two laser cutting apparatuses 14simultaneously trimming one part while another pair of laser cuttingapparatuses 14 simultaneously trims another part. The system 110 alsoincludes the robots 24 transferring the parts to and from the cuttingstation 20, and the two inner chambers 22 with the double doors 16, 18.The system 110 of FIG. 5 also includes the conveyor 38 with the cuttingplatforms 34, 36 sliding the parts to and from the robots 24. However,unlike the system 10 of FIG. 1, the system 110 of FIG. 5 does notinclude the load slide 26 and loading platform 28 conveying the parts inand out of the inner chamber 22. Instead, one of the robots 24 isdisposed in each inner chamber 22, and the human operator 30 preloadsand unloads the parts directly to and from the robot 24. The first doors16 to the inner chambers 22 are located along the same one of the firstwalls 11, and the second doors 18 are each disposed along a second wallfacing perpendicular to the first doors 16 and toward the laser cuttingstation 20. The first doors 16 are between the part loading area 32 andthe inner chambers 22, and the second doors 18 are between the innerchambers 22 and the laser cutting station 20. As shown in FIG. 5, theinner chamber 22 is large enough to hold one of the robots 24 and allowthe robot 24 to rotate at least 90 degrees between the first door 16 andthe second door 18.

In the system 110 of FIG. 5, the operator 30 conveys an untrimmed firstpair of parts 1 through the first door 16 directly to the robot 24,while the second door 18 is closed. The robot 24 then rotates 90degrees, conveys the first pair of parts 1 through the second door 18while the first door 16 is closed, and places the first pair of parts 1on the first cutting platform 34. After the first pair of parts 1 istrimmed, the robot 24 lifts the trimmed first pair of parts 1 off thefirst cutting platform 34, and conveys the parts through the second door18 into the inner chamber 12 while the first door 16 is closed. Therobot 24 then rotates 90 degrees, and conveys the trimmed first pair ofparts 1 through the first door 16 and directly back to the operator 30in the part loading area 32 while the second door 18 is closed. As inthe system 10 of FIG. 1, the preloading and unloading steps on bothsides of the enclosed cell 12 are repeated continuously to maximize thelaser cutting time.

FIG. 6 illustrates the laser cutting system 210 according to a thirdexemplary embodiment, which is even less automatic and requires morelabor than the laser cutting system 110 of FIG. 5. Like the systems 10,110 of FIGS. 1 and 5, the system 210 of FIG. 6 includes two lasercutting apparatuses 14 simultaneously cutting one part while the othertwo laser cutting apparatuses 14 simultaneously trim another part. Thesystem 210 of FIG. 6 also includes the two inner chambers 22 with thedouble doors 16, 18, the two cutting platforms 34, 36 and the conveyor38 sliding the parts to and from the cutting station 20.

However, unlike the systems 10, 110 of FIGS. 1 and 5, the part loadingareas 32 and the inner chambers 22 of the system 210 of FIG. 6 arelocated on opposite sides of the enclosed cell 12. The first doors 16are disposed along first walls 11 facing opposite one another, and thesecond doors 18 are disposed along second walls 23 parallel to the firstdoors 16 and facing toward the laser cutting station 20. In addition,the system 210 of FIG. 6 does not include the robots 24 transferring theparts from the inner chambers 22 to the cutting station 20. Instead, theconveyor 38 extends continuously from one part loading area 32, throughone of the inner chambers 22 and doors 16, 18, through the cuttingstation 20, through the second inner chamber 22 and doors 16, 18, and tothe opposite part loading area 32. The first cutting platform 34 movesback and forth between the pair loading area 32 on the right side of theenclosed cell 12 and the cutting station 20 while the second cuttingplatform 36 moves back and forth between the cutting station 20 and thepart loading area 32 on the left side of the enclosed cell 12,independent of the first cutting platform 34.

In the system 210 of FIG. 6, the operator 30 loads the first pair ofparts 1 onto the first cutting platform 34 in the part loading area 32,the conveyor 38 transfers the first pair of parts 1 through the firstdoor 16 and into the inner chamber 22 while the second door 18 isclosed, and then through the second door 18 while the first door 16 isclosed. The conveyor 38 then transfers the first pair of parts 1directly to the laser cutting station 20. While the first pair of parts1 is being trimmed, the second pair of parts 2 is preloaded and conveyedthrough the double doors 16, 18 on the left side of the enclosed cell12, and waits on the second cutting platform 36 directly adjacent thecutting station 20. As soon as the laser cutting apparatuses 14 finishcutting the first pair of parts 1, the first and second platforms 34, 36immediately move to the right so that the untrimmed second pair of parts2 is disposed at the cutting station 20 and the trimmed first pair ofparts 1 is conveyed back through the same set of double doors 16, 18 andto the part loading area 32 on the right side of the enclosed cell 12.The operator 30 unloads the trimmed first pair of parts 1 directly fromthe first cutting platform 34 and preloads an untrimmed third pair ofparts (not shown) onto the first cutting platform 34 while the secondpair of parts 2 is being trimmed. Again, the preloading and unloadingsteps on both sides of the enclosed cell 12 are preferably repeatedcontinuously to maximize the laser cutting time.

The invention also provides a method for laser cutting the parts. Themethod generally comprises laser cutting one part using the plurality oflaser cutting apparatuses 14 while conveying another part though thedouble doors 16, 18 and into the enclosed cell 12 such that no laserlight can escape the enclosed cell 12 and the lasers 14 can runcontinuously. As illustrated in FIG. 7, the method typically includesconveying a first part through the first door 16 into the inner chamber22 while the second door 18 is closed, followed by conveying the firstpart through the second door 18 into the enclosed cell 12 while thefirst door 16 is closed. The method next includes laser cutting thefirst part in the enclosed cell 12 while conveying a second part throughthe first door 16 into the inner chamber 22 while the second door 18 isclosed, followed by conveying the second part through the second door 18into the enclosed cell 12 while the first door 16 is closed.

The method also generally comprises laser cutting one part using theplurality of laser cutting apparatuses 14 while conveying another partthough the double doors 16, 18 and out of the enclosed cell 12 such thatno laser light can escape the enclosed cell 12 and the laser cuttingapparatuses 14 can run continuously. As illustrated in FIG. 8, themethod includes laser cutting the first part in the enclosed cell 12,followed by laser cutting the second part in the enclosed cell 12. Whilelaser cutting the second part, the method includes conveying the trimmedfirst part through the second door 18 and out of the enclosed cell 12while the first door 16 is closed, followed by conveying the second partthrough the first door 16 and out of the inner chamber 22 while thesecond door 18 is closed.

The method can vary depending on the specific system used, but a firstexemplary method can be conducted using the system 10 shown in FIG. 1.The exemplary method includes disposing a first pair of parts 1 on theloading platform 28 on the right side of the part loading area 32,outside of the enclosed cell 12, and disposing a second pair of parts 2on the other loading platform 28 on the left side of the part loadingarea 32, outside of the enclosed cell 12. The human operator 30 disposesthe metal parts on the part loading platforms 28 in the embodiment ofFIG. 1, but alternatively the metal parts could be automatically placedon the part loading platforms 28 by a robot. Next, the method includesopening the first doors 16 into the associated inner chamber 22 whilethe associated second doors 18 are closed, sliding the pairs of parts 1,2 through the first doors 16 and into the inner chambers 22 while thesecond doors 18 are still closed, closing the first doors 16, and thenopening the second doors 18 to the enclosed cell 12 while the firstdoors 16 are closed. The first pair of parts 1 and second pair of parts2 can be conveyed into the enclosed cell 12 at the same time, ordifferent times.

Next, the first exemplary method includes lifting the pairs of parts 1,2 out of the inner chambers 22 and transferring the pairs of parts 1, 2to the laser cutting station 20. This step is conducted by the robots24. At the onset of the first exemplary method, a first cutting platform34 is disposed to the right of the cutting station 20 and a secondcutting platform 36 is disposed at the cutting station 20. The robot 24on the right side of the cutting station 20 lifts the first pair ofparts 1 out of the inner chamber 22, rotates 90 degrees clockwise, andplaces the first pair of parts 1 on the first cutting platform 34. Whilethe first pair of parts 1 is being transferred to the first cuttingplatform 34, the robot 24 on the left side of the cutting station 20lifts the second pair of parts 2 out of the inner chamber 22, rotates 90degrees counterclockwise, and holds the second pair of parts 2. Themethod then includes sliding the cutting platforms 34, 36 to the left,along the conveyor 38, such that the first cutting platform 34 and thefirst pair of parts 1 are disposed at the cutting station 20 and thesecond cutting platform 36 is disposed to the left of the cuttingstation 20, as shown in FIG. 1.

The first exemplary method next includes cutting the first pair of parts1 using the plurality of laser cutting apparatuses 14. The cutting stepcan include any type of laser trimming or cutting technique. Two of thelaser cutting apparatuses 14 trim one part, and the other two lasercutting apparatuses 14 trim the other part, such that the parts aretrimmed simultaneously. While the first pair of parts 1 is beingtrimmed, the method includes preloading the second pair of parts 2 onthe second cutting platform 36. The robot 24 on the left side of thecutting station 20 preloads the second pair of parts 2 by placing themon the second cutting platform 36, as shown in FIG. 1. Thus, the secondpair of parts 2 is waiting and ready for trimming, so that immediatelyafter the first pair of parts 1 is trimmed, the method includes slidingthe cutting platforms 34, 36 along the conveyor 38 to the right so thatthe second pair of parts 2 is disposed at the cutting station 20 and thefirst pair of parts 1 is disposed to the right of the cutting station20. The only time that the laser cutting apparatuses 14 are off is whenthe conveyor 38 is moving the parts along the conveyor 38 into and outof the cutting station 20, and this time period is very short becausethe second pair of parts 2 is waiting and ready on the second cuttingplatform 36 directly adjacent the cutting station 20.

The method next includes cutting the second pair of parts 2. While thesecond pair of parts 2 is being trimmed, the method includes unloadingthe first pair of parts 1 by lifting them off the first cutting platform34, placing them in the inner chamber 22, and sliding them out of theinner chamber 22. The robot 24 on the right side of the cutting station20 unloads the first pair of parts 1 by lifting them off the firstplatform 34, rotating 90 degrees counterclockwise, and then placing themon the loading platform 28 in the inner chamber 22. The double doors 16,18 are again used to prevent light from escaping the enclosed cell 12 asthe trimmed first pair of parts 1 exit the cell 12. This step includesopening the second door 18, placing the first pair of parts 1 in theinner chamber 22 while the first door 16 is closed, and sliding thefirst pair of parts 1 through the first door 16 and out of the innerchamber 22 while the second door 2 is closed. Since no laser light canescape the enclosed cell 12, the lasers 14 can continue cutting thesecond pair of parts 2 while the first pair of parts 1 exits theenclosed cell 12.

Also while the second pair of parts 2 is being trimmed, the robot 24 onthe right side of the cutting station 20 preloads the third pair ofparts 3 onto the first cutting platform 34 for trimming immediatelyafter the second pair of parts 2 are trimmed. In the embodiment of FIG.1, the robots 24 are capable of holding two pairs of parts at the sametime so that the third pair of parts 3 can be placed on the firstcutting platform 34 within seconds after the first pair of parts 1 isremoved from the first cutting platform 34. For example, the robot 24can include an arm having a part holder on each side of the arm. Therobot 24 can pick up the untrimmed third pair of parts 3 from the innerchamber 22, rotate 90 degrees clockwise, and hold the third pair ofparts 3 on one side of the arm while waiting for the first pair of parts1 to be trimmed. Once the first pair of parts 1 is trimmed, the robot 24then picks up the first pair of parts 1 from the first cutting platform34, on the opposite side of the arm, and places the third pair of parts3 on the first cutting platform 34. Next, the robot 24 rotates 90counterclockwise back to the inner chamber 22, picks up a fourth pair 4of untrimmed parts from the loading platform 28 while still holding thetrimmed first pair of parts 1, and then places the trimmed first pair ofparts 1 on the loading platform 28. The first pair of parts 1 exits theinner chamber 22 and is removed from the loading platform 28 while therobot 24 rotates 90 degrees clockwise and transfers the untrimmed fourthpair of parts 4 to the cutting station 20.

Also while the second pair of parts 2 is being trimmed, the robot 24 onthe left side of the cutting station 20 receives a fifth pair of parts 5through the double doors 16, 18 for trimming immediately after the thirdpair of parts 3. After the second pair of parts 2 is trimmed, the methodincludes sliding the cutting platforms 34, 36 along the conveyor 38 tothe left so that the first platform 34 and third pair of parts 3 isdisposed at the cutting station 20, and the trimmed second pair of parts2 and the second cutting platform 36 is disposed to the left of thecutting station 20. The method then includes cutting the third pair ofparts 3 while unloading the trimmed second pair of parts 2 andpreloading the untrimmed fifth pair of parts 5 using the robots 24, inthe same manner as previously described with regard to the first pair ofparts 1 and the third pair of parts 3. Meanwhile, a sixth pair of parts6 waits on the loading platform 28 on the left side of part loading area32 for subsequent preloading by the robots 24. The laser cuttingapparatuses 14 continuously trim the parts, except when the parts aresliding along the conveyor 38. The first exemplary method also includescontinuously placing untrimmed parts on the loading platforms 28 orremoving trimmed parts from the loading platforms 28, while the lasercutting apparatuses 14 are cutting the parts.

Although the first exemplary method includes cutting the first pair ofparts 1 followed by the second pair of parts 2, the method couldalternatively include cutting the second pair of parts 2 before thefirst pair of parts 1. The method can vary from the exemplary embodimentdescribed, depending on the number of double doors 16, 18, innerchambers 22, and laser cutting apparatuses 14 employed, and depending onwhether the other components are used.

For example, a second exemplary method can be conducted using the system110 of FIG. 5, which includes the robots 24 disposed in the innerchambers 22, and does not include the loading platforms 28 and loadslide 26. The second exemplary method is similar to the first exemplarymethod, except the second exemplary method includes manually preloadingthe parts by lifting the parts through the first door 16 and providingthe parts directly to the robot 24 disposed in the inner chamber 22while the second door 18 is closed, instead of preloading the parts onthe loading platforms 28 of the load slide 26. The method of FIG. 5 thenincludes rotating the robot 24 90 degrees and conveying the partsthrough the second door 18 and to one of the cutting platforms 34, 36while the first door 16 is closed.

As in the first exemplary method, when the first pair of parts 1 isbeing trimmed, the second pair of parts 2 waits on the second cuttingplatform 36 to the left of the cutting station 20. Once the first pairof parts 1 is trimmed, the first cutting platform 34 and the secondcutting platform 36 slides to the right so that the trimmed first pairof parts 1 can be unloaded by the robot 14 and the second pair of parts2 is located at the cutting station 20 for cutting by the laser cuttingapparatuses 14. Also, like the first exemplary method, the only timethat the laser cutting apparatuses 14 are off is when the conveyor 38 ismoving the parts into and out of the cutting station 20, and this timeperiod is very short because the second pair of parts 2 is waiting andready on the second cutting platform 36 directly adjacent the cuttingstation 20.

In the second exemplary method, the robot 14 lifts the trimmed firstpair parts 1 off of the cutting platform 34, moves through the seconddoor 18 to the inner chamber 22 while the first door 16 is closed, androtates 90 degrees to the first door 16. The operator 30 then manuallyunloads the trimmed first pair of parts 1 from the robot 24 and preloadsan untrimmed third pair of parts (not shown) to the robot 24 forsubsequent cutting. The parts are continuously preloaded and unloaded onboth sides of the enclosed cell 12 while the laser cutting apparatuses14 trim other parts to maximize the laser cutting time.

A third exemplary method can be conducted using the system 210 of FIG.6, which includes the conveyor 38 extending through the enclosed cell12, and no robots 24. The method includes manually preloading anuntrimmed first pair of parts 1 on the right side of the enclosed cell12 by lifting the parts through the first door 16 and placing the partson the first cutting platform 34 of the conveyor 38 while the seconddoor 18 is closed. The method then includes transferring the first pairof parts 1 along the conveyor 38 through the second door 18 while thefirst door 16 is closed and then directly to the cutting station 20. Asin the other exemplary methods, two of the laser cutting apparatuses 14simultaneously trim one part while the other two laser cuttingapparatuses 14 simultaneously trim another part.

While the first pair of parts 1 is being trimmed, the second pair ofparts 2 is preloaded and conveyed through the double doors 16, 18 on theleft side of the enclosed cell 12, and waits on the second cuttingplatform 36 directly adjacent the cutting station 20. As soon as thelaser cutting apparatuses 14 finish cutting the first pair of parts 1,the method includes immediately conveying both the first and secondplatforms 34, 36 to the right so that the untrimmed second pair of parts2 is disposed at the cutting station 20. The trimmed first pair of parts1 is conveyed back through the same set of double doors 16, 18 and tothe part loading area 32 on the right side of the enclosed cell 12. Asin the other exemplary methods, the only time that the laser cuttingapparatuses 14 are off is when the conveyor 38 is moving the parts intoand out of the cutting station 20, and this time period is very shortbecause the second pair of parts 2 is waiting and ready on the secondcutting platform 36 directly adjacent the cutting station 20.

In the exemplary method of FIG. 6, the operator 30 unloads the trimmedfirst pair of parts 1 directly from the first cutting platform 34 andpreloads an untrimmed third pair of parts (not shown) onto the firstcutting platform 34 while the second pair of parts 2 is being trimmed.The untrimmed third pair of parts is conveyed through the double doors16, 18 on the right side of the enclosed cell 12 and waits adjacent tothe cutting station 20 for the laser cutting apparatuses 14 to finishcutting the second pair of parts 2. As soon as the laser cuttingapparatuses 14 finish cutting the second pair of parts 2, the methodincludes moving both the first and second cutting platforms 34, 36 tothe left so that the third pair of parts is disposed at the cuttingstation 20. The third pair of parts is then trimmed. The preloading andunloading steps on both sides of the enclosed cell 12 are repeatedcontinuously to maximize the laser cutting time.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings and may be practicedotherwise than as specifically described while within the scope of theclaims.

What is claimed is:
 1. A laser cutting method, comprising the steps of:laser cutting at least one first part in a cell enclosed by a pluralityof first walls; maintaining at least one second part in the enclosedcell adjacent the at least one first part while laser cutting the atleast one first part; laser cutting the at least one second part in thecell enclosed by the plurality of first walls; and transferring at leastone third part through a first door and into a first inner chamber whilea second door connecting the first inner chamber to the enclosed cell isclosed and while laser cutting the at least one first part or the atleast one second part.
 2. The method of claim 1 including laser cuttingthe at least one second part after laser cutting the at least one firstpart; transferring the at least one first part through the second doorinto the first inner chamber and out of the enclosed cell while thefirst door is closed and while laser cutting the at least one secondpart; and transferring the at least one third part through the firstdoor and into the first inner chamber while laser cutting the at leastone first part.
 3. The method of claim 2 including transferring the atleast one third part from the first chamber through the second door andinto the enclosed cell while the first door is closed, and maintainingthe at least one third part in the enclosed cell adjacent the at leastone second part while laser cutting the at least one second part.
 4. Themethod of claim 3 including transferring the at least one first partthrough the first door and out of the first inner chamber while thesecond door is closed; and transferring at least one fourth part throughthe first door and into the first inner chamber while the second door isclosed and while laser cutting the at least one second part.
 5. Themethod of claim 4 including transferring at least one fifth part througha first door and into a second inner chamber while a second doorconnecting the second inner chamber to the enclosed cell is closed andwhile laser cutting the at least one second part.
 6. The method of claim5 including laser cutting the at least one third part after lasercutting the at least one second part; transferring the at least onesecond part through the second door out of the enclosed cell and intothe second inner chamber while the first door is closed and while lasercutting the at least one third part.
 7. The method of claim 1 includingtransferring the at least one third part through the second door fromthe first inner chamber to the enclosed cell; and rotating the at leastone third part 90 degrees after transferring the at least one of thirdpart through the second door and before laser cutting the at least onethird pan.
 8. The method of claim 1, wherein the step of transferringthe at least one third part through a first door and into a first innerchamber while a second door connecting the first inner chamber to theenclosed cell is closed and while laser cutting the at least one firstpart or the at least one second part.
 9. The method of claim 1, whereinthe laser cutting step is conducted at a laser cutting station, and atleast one robot transfers at least one of the parts to the laser cuttingstation.
 10. The method of claim 9, wherein the at least one robottransfers at least one of the parts from the first inner chamber to thelaser cutting station and/or from the laser cutting station to the firstinner chamber.
 11. The method of claim 9, including a second innerchamber, the at least one robot includes a first robot and a secondrobot, the first robot is located between the first inner chamber andthe laser cutting station, and the second robot is located between thesecond inner chamber and the laser cutting station.
 12. The method ofclaim 11, wherein the robots convey the parts to and from the first andsecond inner chambers simultaneously.
 13. The method of claim 1including sliding the parts between the first inner chamber and thelaser cutting station.
 14. A laser cutting system, comprising: a cellenclosed by a plurality of first walls; at least one laser cuttingapparatus disposed in said enclosed cell for cutting at least one part;at least one inner chamber disposed along said enclosed cell, said innerchamber enclosed by at least one of said first walls and at least onesecond wall; a first door disposed along one of said first wallsenclosing said inner chamber for allowing the at least one part to passtherethrough; a second door disposed along one of said second wallsenclosing said inner chamber for allowing the at least one part to passtherethrough, wherein only one of said doors is open at a time whilesaid at least one laser cutting apparatus cuts the at least one part;and at least one robot for transferring said at least one part to and/orfrom a laser cutting station including said at least one laser cuttingapparatus.
 15. The laser cutting system according to claim 14, whereinsaid at least one robot includes a material handling robot.
 16. Thelaser cutting system according to claim 14, wherein said at least onerobot transfers said at least one part from said at least one innerchamber to said laser cutting station and/or from said laser cuttingstation to said at least one inner chamber.
 17. The laser cutting systemaccording to claim 14, wherein said at least one inner chamber includesa first inner chamber and a second inner chamber, said at least onerobot includes a first robot and a second robot, said first robot islocated between said first inner chamber and said laser cutting station,said second robot is located between said second inner chamber and saidlaser cutting station.
 18. The laser cutting system according to claim17, wherein said at least one part includes a plurality of parts, andsaid robots convey said parts to and from said first and second innerchambers simultaneously.
 19. The laser cutting system according to claim14 including a slide between said at least one inner chamber and saidlaser cutting station for conveying said at least one part to and/orfrom said laser cutting station.
 20. The laser cutting system accordingto claim 14 including least one cutting platform which slides the atleast one part in and/or out of the laser cutting station.